From 063f6b5ca9fc31db61e7204879245ddf3408a29c Mon Sep 17 00:00:00 2001
From: Owen <owen@txv.io>
Date: Fri, 4 Sep 2026 12:31:04 -0400
Subject: [PATCH] Basic DNS config send empty for olm

---
 server/routers/olm/dnsConfig.ts               | 20 +++++++++++++++++++
 .../routers/olm/handleOlmRegisterMessage.ts   |  2 ++
 2 files changed, 22 insertions(+)
 create mode 100644 server/routers/olm/dnsConfig.ts

diff --git a/server/routers/olm/dnsConfig.ts b/server/routers/olm/dnsConfig.ts
new file mode 100644
index 000000000..441246764
--- /dev/null
+++ b/server/routers/olm/dnsConfig.ts
@@ -0,0 +1,20 @@
+import config from "@server/lib/config";
+
+// Mirrors the optional fields on the olm client's TunnelConfig - any field
+// present here overrides the value the olm client is otherwise locally
+// configured with; an absent field leaves the client's own config alone.
+export type OlmDnsConfig = {
+    upstreamDns?: string[];
+    overrideDns?: boolean;
+    tunnelDns?: boolean;
+    matchDomains?: string[];
+};
+
+export function buildOlmDnsConfig(): OlmDnsConfig | undefined {
+    return {
+        upstreamDns: undefined,
+        overrideDns: undefined,
+        tunnelDns: undefined,
+        matchDomains: undefined
+    };
+}
diff --git a/server/routers/olm/handleOlmRegisterMessage.ts b/server/routers/olm/handleOlmRegisterMessage.ts
index 35fb95ca5..693920950 100644
--- a/server/routers/olm/handleOlmRegisterMessage.ts
+++ b/server/routers/olm/handleOlmRegisterMessage.ts
@@ -15,6 +15,7 @@ import { encodeHexLowerCase } from "@oslojs/encoding";
 import { sha256 } from "@oslojs/crypto/sha2";
 import { getUserDeviceName } from "@server/db/names";
 import { buildSiteConfigurationForOlmClient } from "./buildConfiguration";
+import { buildOlmDnsConfig } from "./dnsConfig";
 import { OlmErrorCodes, sendOlmError } from "./error";
 import { handleFingerprintInsertion } from "./fingerprintingUtils";
 import { build } from "@server/build";
@@ -512,6 +513,7 @@ export const handleOlmRegisterMessage: MessageHandler = async (context) => {
                               tunnelIP: `${clientSubnet.split("/")[0]}/${exitNode.address.split("/")[1]}` // we need to use the exit node's subnet mask here because the client will be using the exit node's subnet mask for its routing table so we can address it
                           }
                         : undefined,
+                dnsConfig: buildOlmDnsConfig(),
                 chainId: chainId
             }
         },